Sau vs si, What's the Difference?

Which to use

“Sau” is a noun and “si” is a pronoun - they look or sound alike but fill different roles in a sentence.

#49,171
“Sau” frequency rank: #482
“si” frequency rank: 49653
confusion score

Side-by-Side Comparison

Feature	Sau	si
Definition	porco	refere-se à terceira pessoa, indica reflexividade e é usado após preposição (a, de, em, contra, sobre, por, etc., exceto com)

Where the eye mixes Sau and si

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

2 ch

Look-alike desk: Sau vs si

These two trip readers on the page rather than in the ear: Sau is /zaʊ̯/ while si is /ˈsi/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (noun vs pronoun), which is usually the fastest check. Our composite confusion score for this pair is 49653, derived from the frequency rank of both members and their visual similarity.

Sau is recorded at frequency rank #49,171, classified as anoun, pronounced /zaʊ̯/. si is at rank #482, tagged as apron, pronounced /ˈsi/.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 49653, this pair ranks #15,331 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of Sau vs si

Shared letters: s. Private to "Sau": au. Private to "si": i.

"Sau" · 3 letters · shape CVV · "si" · 2 letters · shape CV

Frequently Asked Questions

Is swapping "Sau" for "si" ever safe?

No - they are not even the same part of speech. "Sau" is a noun and "si" a pronoun, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "Sau" or "si"?

"si" is the more common of the two: it sits at frequency rank #482 in our Portuguese list, against #49,171 for "Sau". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "Sau" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "si" - compare definitions side by side with the headword page. Word entry
This pair ranks #15,331 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"Sau" and "si" also get mixed up with nearby pairs, the highest-scored neighbour is "Sau vs soap". Nearby pair

Confusion rank #15,331 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.